Lag Discussion for Dummies

If this topic has been done before, I do apologize.

What I was hoping ot do here was get some helpful tips about lab in very low techy speak, so that those of us that may be pretty good builders, but not generally computer nerds might have a chance at actually understanding it.

I don't want to limit this to just answering a few questions I have posed ... throw in whatever you want ... but the point is that if you get ultra-techy speak on me, I will not understand you anyway, so maybe be a dear and keep it simple, for the simple minded (meaning me).

A few questions, etc ...

Does making a megaprim phantom, reduce the lag? This is what I have been told. True?

What about mega prims ... are they also mega-lag? I would like to use mega's to save prims ... sidewalks, floors, walls, etc ... but don't want to cause a lot of lag doing it. If you used a 20m x 50m mega to replace 10x 10m x 10m sections of road, is this a good save, lag wise? People have told me the ten prims will lag you more than the single mega.

Things that move and rotate ... we did this thing where we made five rotating signs, and the lag was pretty noticable. Then we removed them and put out five rotating seaguls, and didn't notice anything at all. WTF ... aren't they both just things that rotate?

The mysterious wall section ... I have these three animals, high dollar, high prims, all sculpted ... they rez really fast and don't seem to bring the speed of the sim down at all ... BUT, I have these two wall sections, 10m x 10m cubes, with the same texture I'm using on a bunch of other wall sections, but these two take forever to load. I've even deleted them and dragged copies of parts that seem to rez fast, but they still rez slow. Clueless (which I guess you could already tell).

Sea spray, waves, flexy plants ... laggy, or not?

Last question (for now, haha) ... if you had to list the top laggy things, and the top things that people say are alggy, but are not, what would they be? ... and, if you have any tips on keeping lag low, I'm all ears, or eyes as it may be.

Lag is a curious beast. There are many different kinds, so asking if something causes more lag than another thing isn't always an easy question to answer.

Network lag, caused by low bandwidth, and exacerbated by downloading large textures (including sculpties, which are extra textures to d/l).

Client-side lag, usually caused by not having a PC powerful enough for the scene you are trying to render: poor graphics card specs, low-end processor, not enough memory. Exacerbated by rendering lots of avatars, flexies, reflections, alphas, prims with lots of polys, objects rotating under llTargetOmega and particles. And of course, running other software alongside SL.

Server-side lag. Less sure of this one, but likely to be lots of scripts & physics events happening in a sim.

The lagginess, or not, of megaprims has been discussed recently, so I'd suggest you look for that thread for some answers. I don't think we got to any definite conclusions though.

<edit> URL for the recent megaprim thread: /327/c1/314484/1.html

Thank you Kelli ... the way you discussed Network, Client and Server side lag was easy for even me to understand.

Would you mind if I asked what "prims with lots of polys" and "TargetOmega" actually means?

I have actually looked at a lot of the other discussions, but became quickly lost. While most say I'm a killer builder, I lack the technical expertise with programming languages to really understand where those threads are going. My goal here was to get some ideas on things that I can try for myself.

Prims with lots of polys, i.e. ploygons, are harder the render than ones with few. Cubes are low-polygon count (six faces). Toruses are high-polygon - all the curves are split into many small triangles. If the prims is cut or hollow, there are more sides, therefore more polys.

llTargetOmega is the script command for client-side rotation. Most things that rotate constantly use this command, as opposed to objects that rotate a set amount, like doors. It's called 'omega' because the omega symbol is used to represent angular momentum in physics (and not a lot of people know that).

About one of you original questions on rotating signs vs rotating birds. They would have been using TargetOmega. I can't be sure why one was more laggy than the other. It might be that the signs were more complicated objects than the birds, with more polys to render. There might have been other stuff in play: maybe they used more textures.

Thanks Kelli ...

Must be a boring discussion ... must not have enough drama.